2219-T87铝合金拉锻式摩擦塞补焊接头组织及性能

对6 mm厚的2219-T87铝合金板进行了拉锻式摩擦塞补焊试验，对焊接接头的微观组织、显微硬度、抗拉强度及拉伸断口进行了观察与测试. 结果表明，采用优化的摩擦塞补焊工艺可实现2219-T87铝合金母材和2219-T87铝合金塞棒的冶金连接. 拉锻式摩擦塞补焊过程中，塞棒承受拉应力，应优化接头设计和焊接工艺参数从而防止塞棒被拉断. 未焊合是接头的主要缺陷，易出现在接头的近上表面处. 焊缝区发生明显软化，最低硬度出现在靠近连接界面的塞棒热力影响区，最低值为84.4 HV. 接头的抗拉强度可达326.4 MPa，断后伸长率可达4.45%，抗拉强度和断后伸长率分别为母材的71.7%和44.5%，拉伸断口呈韧窝形貌.

Microstructures and properties of 2219-T87 aluminum alloy friction pull plug welds

Friction pull plug welding (FPPW) experiments were performed for 6mm thick 2219-T87 aluminum alloy. The microstructures, microhardness, tensile strength and tensile fracture surface of FPPW joints were observed and tested respectively. It is verified that metallurgical combination was realized between 2219-T87 plate and 2219-T87 plug using optimized FPPW process. In FPPW process, plug was subjected to tensile stress. Joint design and welding parameters are optimized to prevent plug from being broken off. Lack of bonding was the main defect for FPPW joint, which was easily formed near the upper surface. Softening was observed in the weld zone, the minimum hardness (84.4 HV) appeared in plug thermo-mechanical affected zone. The tensile strength and elongation of FPPW joint can reach to 326.4 MPa and 4.45%, which are equivalent to 71.7% and 44.5% of the base metal. The tensile fracture morphologies are characterized by dimples.